In Puerto Rico, Gov. Ricardo Rossello announced that at least three people died during the storm, the Reuters news agency reports. A 79-year old bedridden woman died after falling while being taken to a shelter, the governor said in a statement. A woman in Camuy was electrocuted in her home, and a man died from injuries sustained during a traffic accident in Canovanas.

On the independent island of Barbuda, a 2-year-old child was killed as a family tried to escape a damaged home during the storm. On the British island of Anguilla, at least one person has died, the Caribbean Disaster Management Agency said, adding that 90 percent of roads on the island are impassible.

French Prime Minister Edouard Philippe said four people were confirmed dead and about 50 injured on the island of St. Martin, which is split between Dutch and French control.

The death toll on St. Martin was lower than one given earlier Thursday by France's interior minister, who said eight people had been killed on French Caribbean territories. An official in Philippe's office told The Associated Press only four people were confirmed dead after a re-evaluation of the damage. The official said the toll could rise as rescuers reach the scene.

In St. Maarten, Dutch Interior Minister Ronald Plasterk said one person was confirmed dead in the former colony. He also said there are a number of injuries and that the authorities still only have an "incomplete picture" of the damage.

French Interior Minister Gerard Collomb said 100,000 food rations were sent to St. Barts, which also got slammed, and St. Martin, the equivalent of four days of supplies.

"It's a tragedy, we'll need to rebuild both islands," he said. "Most of the schools have been destroyed."

Irma blacked out much of Puerto Rico, raking the U.S. territory with heavy wind and rain while staying just out to sea, and it headed early Thursday toward the Dominican Republic and Haiti.

In Haiti, Interior Minister Max Rudolph Saint-Albin ordered the evacuation of coastal areas in the north of the country. That includes people living in and around Port-de-Paix and the island known as Il de la Tortue. The country is expected to be spared a direct hit from Irma but heavy rains and high surf could trigger dangerous floods in the impoverished country.

The U.S. National Hurricane Center in Miami issued a hurricane watch for the Florida Keys and on the South Florida mainland from Jupiter Inlet southward and around the peninsula to Bonita Beach. The center noted that Hurricane Irma was still an "extremely dangerous" Category 5 hurricane, although its winds had decreased slightly from 180 mph to 175 mph.

Florida Gov. Rick Scott said evacuation orders have been issued in the Keys and parts of Broward County, Collier County, Hendry County and Miami-Dade County, where the mayor issued evacuation orders for certain areas.

Floridians who are unable to evacuate were urged to call (800) 342-3557 before the storm hits the state. Scott said 31,000 people were estimated to have evacuated the Keys as of Wednesday night.

The U.S. National Hurricane Center (NHC) released its 5 p.m. ET advisory to report that the center of the storm was about 40 miles south of Grand Turk Island the eye of Irma should continue to move between Hispaniola and the Turks and Caicos Islands this evening. Irma was moving west-northwest at around 16 mph, according to the hurricane center. Hurricane warnings were dropped for all of Puerto Rico, Vieques, and Culebra.

A map shows the projected path of Hurricane Irma as of 5 p.m. ET on Sept. 7, 2017.

U.S. National Hurricane Center

The NHC said in its advisory that the government of Cuba has issued a hurricane warning for the Cuban provinces of Camaguey, Ciego de Avila, Sancti Spiritus and Villa Clara. This includes the Cuban Keys along the north shore of these provinces.

A hurricane warning means that hurricane conditions are expected somewhere within the warning area. Preparations to protect life and property should be rushed to completion.

Hurricane Irma has had 185 mph winds longer than any other hurricane in recorded history, CBS News' weather producer David Parkinson reports.

Parkinson adds that although it appeared Irma had hit peak intensity earlier, it is going through another eyewall replacement cycle, which means the strongest winds will extend further from the storm. It is possible winds bump up to 190 mph Thursday.

An animation provided by the National Oceanic and Atmospheric Administration via the National Hurricane Center shows Hurricane Irma churning north of the Dominican Republic early on Sept. 7, 2017, on a path toward southern Florida.

NOAA/NHC

"The storm has exceeded strength expectations thus far, and there is nothing ahead of the storm to indicate large scale weakening should take place," Parkinson writes.

Communications were difficult with areas hit by Irma, and information on damage trickled out.

Nearly every building on Barbuda was damaged when the hurricane's core crossed almost directly over the island early Wednesday and about 60 percent of its roughly 1,400 residents were left homeless, Antigua and Barbuda Prime Minister Gaston Browne told The Associated Press.

"It is just really a horrendous situation," Browne said after returning to Antigua from a plane trip to the neighboring island.

He said roads and telecommunications systems were wrecked and recovery would take months, if not years. A 2-year-old child was killed as a family tried to escape a damaged home during the storm, Browne told the AP.

A view of the aftermath of Hurricane Irma is seen in Sint Maarten, the Dutch part of the island of St. Martin in the Caribbean, Sept. 7, 2017.

Netherlands Ministry of Defence/Handout via Reuters

On St. Thomas in the U.S. Virgin Islands, Laura Strickling spent 12 hours hunkered down with her husband and 1-year-old daughter in a boarded-up basement apartment with no power as the storm raged outside. They emerged to find the lush island in tatters. Many of their neighbors' homes were damaged and once-dense vegetation was largely gone.

"There are no leaves. It is crazy. One of the things we loved about St. Thomas is that it was so green. And it's gone," Strickling said. "It will take years for this community to get back on its feet."

Photos and video of St. Martin circulating on social media showed major damage to the Philipsburg airport and heavy flooding in the coastal village of Marigot. On St. Barts, Irma ripped off roofs and knocked out electricity.

"There is no power, no gasoline, no running water. Houses are under water, cars are floating through the streets, inhabitants are sitting in the dark, in ruined houses and are cut off from the outside world," he said.

A car was turned onto its side in Marigot, Saint Martin, after Hurricane Irma hit the Caribbean island Sept. 6, 2017.

Getty

More than a million people in Puerto Rico were without power - nearly 70 percent of customers of Puerto Rico's Electric Power Authority. Puerto Rican Gov. Ricardo Rossello said that crews were investigating and until they know the extent of the damage, "it will be difficult to estimate how long the power outage will last." Fourteen hospitals were using generators after losing power, and trees and light poles were strewn across roads.

Rossello added that ports on the island were still closed, and it's unclear when commercial flights will resume. Nearly 50,000 were without water, the U.S. territory's emergency management agency said in the midst of the storm.

Puerto Rico's public power company warned before the storm hit that some areas could be left without power from four to six months because its staff has been reduced and its infrastructure weakened by the island's decade-long economic slump.

State maintenance worker Juan Tosado said he was without power for three months after Hurricane Hugo in 1989. "I expect the same from this storm. It's going to be bad," he said.

President Trump approved an emergency declaration for the U.S. Virgin Islands and Puerto Rico, allowing the Federal Emergency Management Agency and other agencies to remove debris and give other services that will largely be paid for by the U.S. government.

Pauline Jackson, a 59-year-old registered nurse from Florida visiting Puerto Rico, said she had tried to leave before the storm but all flights were sold out.

She has a reservation to fly out Friday and is worried about her home in Tampa. "When you're from Florida, you understand a Category 5 hurricane," she said.

The U.S. National Hurricane Center predicted Irma would remain at Category 4 or 5 for the next day or two as passes just to the north of the Dominican Republic and Haiti on Thursday, nears the Turks & Caicos and parts of the Bahamas by Thursday night and skirts Cuba on Friday night into Saturday. It will then likely head north toward Florida.

The storm was expected to hit Florida sometime Sunday, and the governor said he planned to activate 7,000 National Guard soldiers by Friday. He warned that Irma is "bigger, faster and stronger" than Hurricane Andrew, which wiped out entire neighborhoods in south Florida 25 years ago.

Scott urged all gas stations in Florida to stay open as long as possible to accommodate evacuees. He even announced at his midday Thursday news conference that police escorts will get gas station employees out safely if necessary just ahead of the storm.

Scott said authorities were escorting fuel tankers through traffic and to gas stations as quickly as possible.

Experts worried that Irma could rake the entire Florida east coast from Miami to Jacksonville and then head into Savannah, Georgia, and the Carolinas, striking highly populated and developed areas.

"This could easily be the most costly storm in U.S. history, which is saying a lot considering what just happened two weeks ago," said Brian McNoldy, a hurricane researcher at the University of Miami.